Results 1 to 10 of about 23,536 (235)

Multi-messenger emission characteristics of blazars [PDF]

Frontiers in Astronomy and Space Sciences
Multi-messenger observations and theories of astrophysical objects are rapidly becoming a critical research area in the astrophysics scientific community. In particular, point-like objects such as BL Lacertae (BL Lac) objects, flat-spectrum radio quasars
Ronald Gamble, Ronald Gamble, Ronald Gamble, Jordan Forman, Amethyst Barnes, Gokul Srinivasaragavan, Gokul Srinivasaragavan, Isiah Holt, Isiah Holt, Marvin Jones, Marvin Jones   +10 more
doaj   +2 more sources

A Model of Polarisation Rotations in Blazars from Kink Instabilities in Relativistic Jets

Galaxies, 2017
This paper presents a simple model of polarisation rotation in optically thin relativistic jets of blazars. The model is based on the development of helical (kink) mode of current-driven instability.
Krzysztof Nalewajko
doaj   +4 more sources

Probing Neutrino Production in Blazars by Millimeter VLBI [PDF]

Galaxies, 2023
The advancement of neutrino observatories has sparked a surge in multi-messenger astronomy. Multiple neutrino associations among blazars are reported while neutrino production sites are located within their central (sub)parsecs.
Yuri Y. Kovalev, Alexander V. Plavin, Alexander B. Pushkarev, Sergey V. Troitsky   +3 more
doaj   +2 more sources

Multiwavelength Properties of Blazars [PDF]

Advances in Space Research, 1999
Blazar spectral energy distributions (SEDs) are double peaked and follow a self-similar sequence in luminosity. The so-called "blue" blazars, whose first SED component peaks at X-ray energies, are TeV sources, although with a relatively small fraction of
Urry, C. Megan
core   +6 more sources

Polarized blazar X-rays imply particle acceleration in shocks. [PDF]

Nature, 2022
Liodakis I, Marscher AP, Agudo I, Berdyugin AV, Bernardos MI, Bonnoli G, Borman GA, Casadio C, Casanova VC, Cavazzuti E, Rodriguez Cavero N, Di Gesu L, Di Lalla N, Donnarumma I, Ehlert SR, Errando M, Escudero J, Garcı A-Comas M, Agı S-González B, Husillos C, Jormanainen J, Jorstad SG, Kagitani M, Kopatskaya EN, Kravtsov V, Krawczynski H, Lindfors E, Larionova EG, Madejski GM, Marin F, Marchini A, Marshall HL, Morozova DA, Massaro F, Masiero JR, Mawet D, Middei R, Millar-Blanchaer MA, Myserlis I, Negro M, Nilsson K, O'Dell SL, Omodei N, Pacciani L, Paggi A, Panopoulou GV, Peirson AL, Perri M, Petrucci PO, Poutanen J, Puccetti S, Romani RW, Sakanoi T, Savchenko SS, Sota A, Tavecchio F, Tinyanont S, Vasilyev AA, Weaver ZR, Zhovtan AV, Antonelli LA, Bachetti M, Baldini L, Baumgartner WH, Bellazzini R, Bianchi S, Bongiorno SD, Bonino R, Brez A, Bucciantini N, Capitanio F, Castellano S, Ciprini S, Costa E, De Rosa A, Del Monte E, Di Marco A, Doroshenko V, Dovčiak M, Enoto T, Evangelista Y, Fabiani S, Ferrazzoli R, Garcia JA, Gunji S, Hayashida K, Heyl J, Iwakiri W, Karas V, Kitaguchi T, Kolodziejczak JJ, La Monaca F, Latronico L, Maldera S, Manfreda A, Marinucci A, Matt G, Mitsuishi I, Mizuno T, Muleri F, Ng SC, Oppedisano C, Papitto A, Pavlov GG, Pesce-Rollins M, Pilia M, Possenti A, Ramsey BD, Rankin J, Ratheesh A, Sgró C, Slane P, Soffitta P, Spandre G, Tamagawa T, Taverna R, Tawara Y, Tennant AF, Thomas NE, Tombesi F, Trois A, Tsygankov S, Turolla R, Vink J, Weisskopf MC, Wu K, Xie F, Zane S.   +127 more
europepmc   +3 more sources

Classification of unassociated fermi-LAT sources [PDF]

ITM Web of Conferences, 2022
The Large Area Telescope (LAT) on board NASA’s Fermi Gamma-ray Space telescope has detected 5788 sources in the 4FGL catalogue. Among them, 271 have been associated to pulsars, 3436 to blazars, and 1782 remain unassociated sources.
Meng Qiyu
doaj   +1 more source

Testing the Blazar Sequence with Spectra of Recently Discovered Dim Blazars from the Fermi Unassociated Catalog

The Astrophysical Journal, 2023
Recent works have developed samples of blazars from among the Fermi Large Area Telescope unassociated sources via machine-learning comparisons with known blazar samples. Continued analysis of these new blazars tests the predictions of the blazar sequence
Stephen Kerby, Abraham D. Falcone
doaj   +1 more source

Unifying MeV-blazars with GeV-blazars [PDF]

, 2002
We demonstrate that the spectral differences between Flat Spectrum Radio Quasars (FSRQ) with steep gamma-ray spectra (MeV-blazars) and FSRQ with flat gamma-ray spectra (GeV-blazars) can be explained by assuming that in the MeV-blazars, the production of gamma-rays is dominated by Comptonization of infrared radiation of hot dust, whereas in the GeV ...
Blazejowski, M., Sikora, M., Moderski, R., Madejski, G.   +3 more
openaire   +3 more sources

X-ray Flux and Spectral Variability of the TeV Blazars Mrk 421 and PKS 2155-304

Galaxies, 2020
We reviewed X-ray flux and spectral variability properties studied to date by various X-ray satellites for Mrk 421 and PKS 2155-304, which are TeV emitting blazars. Mrk 421 and PKS 2155-304 are the most X-ray luminous blazars in the northern and southern
Alok C. Gupta
doaj   +1 more source

Exploring TeV Candidates of Fermi Blazars through Machine Learning

The Astrophysical Journal, 2023
In this work, we make use of a supervised machine-learning algorithm based on Logistic Regression (LR) to select TeV blazar candidates from the 4FGL-DR2/4LAC-DR2, 3FHL, 3HSP, and 2BIGB catalogs.
J. T. Zhu, C. Lin, H. B. Xiao, J. H. Fan, D. Bastieri, G. G. Wang   +5 more
doaj   +1 more source